On Mon, Jul 19, 2010 at 11:13 PM, Wahyu Darmawan wahyu.darmawan@gmail.com wrote:

Hi all,

I have problem with my servers. I use two of HP Blade Servers and RHEL 4.6 installed on them, and have IBM DS4700 connected to them.

In those servers are running RHCS (Red Hat Cluster Suite) with GFS for handling Oracle Database.

Yesterday, I had missing one partition from the storage, suddenly. I called IBM and they suggested to use RDAC.

They suggest this because it's what they're familiar with and what they support.

The question is, Why should use IBM RDAC for multipath on RHEL 4, and why HP Blade + HP EVA Storage don't use any addition plugins software to keep server + storage connection?

I'm not sure if the dm-multipath in centos4 is recent enough, but in centos5 you don't need to use the rdac stuff at all. You can simply configure the ds4700 using the rhel device-mapper-multipath package and a couple modifications in the file for wwid and other bits. You might check into see if this is the case for centos4 as well. We have a DS4700 as well though with IBM blades, and the mpp (rdac) drivers are a royal PITA when it comes to updating the kernel. I would look to see if this blog post helps you -> http://www.bofh-hunter.com/2009/09/02/dm-multipath-and-the-ds4700/